Chapter 2.6, Problem 97E

The bar graph shows the population of the United States in millions for seven selected years.

Here are two functions that model the data:

$\begin{array}{cc}M(x)=1.48x+115.1& \begin{array}{l}\text{Male}\text{U}\text{.S}\text{.pepolalias, }M(x),\text{is aillises,}\\ xyearafter1985\end{array}\\ F(x)=1.44x+120.9& \begin{array}{l}\text{Female}\text{U}\text{.S}\text{.pepolalias, }F(x),\text{is aillises,}\\ xyearafter1985\end{array}\end{array}$

Use the functions to solve Exercises 97-98.

a. Write a function that models the total U.S. population for the years shown in the bar graph.

b. Use the function from part (a) to find the total U.S. population in 2010.

c. How well does the result in part (b) model the actual total U.S. population in 2010 shown by the bar graph?